1. Field of the Invention
The present invention relates to an interchangeable lens and to a camera body.
2. Description of Related Art
It is per se known to provide bidirectional communication between an interchangeable lens and a camera body by three wire type synchronous communication. With such a communication format that is implemented using three signal lines, one line is allocated to a clock signal, and the remaining two signal lines are allocated to communication from the lens to the body and to communication from the body to the lens. When the clock signal is output from the lens or from the body, the lens and the body both perform output of data simultaneously in synchrony with this clock signal. In other words, data transmission from the lens to the body and data transmission from the body to the lens are performed simultaneously. For example, an image-capturing device is described in Japanese Laid-Open Patent Publication 2000-105402 (Patent Document #1) that performs bidirectional communication of the type described above using a group of six contact points.